Averaging with pentane



Patented Aug. 20, 1946 UNITED STATES PATENT OFFICE AVERAGING WITHPENTANE Robert E. Burk, Novelty, Ohio, assignor to The Standard OilCompany, Cleveland, Ghio, a corporation of Ohio No Drawing. ApplicationAugust 9, 1944,

- Serial No. 548,807

Claims. 1

drocarbons of intermediate molecular weight, a

process termed averaging.

A preferred and important embodiment of the invention comprises the useof a normal pentane containing fraction as the lighter hydrocarbon, anda liquid hydrocarbon boiling above the gasoline range as the heavierhydrocarbons, to produce gasoline of desirable properties.

It is one of the objects of the invention to utilize normal pentane asone of the raw materials in making more valuable hydrocarbon products.

A further object of the invention is to utilize heavier hydrocarbonfractions, such as kerosene or naphthas, in the formation ofhydrocarbons of lower molecular weight, such as gasoline, without theproduction of large amounts of unsaturated hydrocarbons or fixed gases,and also without the destructive influences and losses incident toconventional methods of cracking.

An additional object of the invention is to utilize both a pentanecontaining hydrocarbon fraction and a heavier hydrocarbon fractionsimultaneously in a single reaction to produce valuable productsintermediate said fractions resulting from a net consumption of both ofthem at the same time.

An additional object of the invention is to provide a process in which amixture of butanes and pentanes may be used as the lighter fraction inan averaging process resulting in a net con- .sumption of normal pentaneto form more valuable hydrocarbons.

Still a further object of the invention is the provision of a process inwhich a butane and pentane containing lighter fraction may be used asthe lighter hydrocarbon in an averaging reaction and the proportionsadjusted so as to result in .a net consumption of the butanes along withthe pentanes.

A further object is to provide a process in which the normal pentane inthe lighter fraction is used in the manufacture of higher hydro 2carbons as well as converted to isobutane which may be fractionated andused in other processes such as alkylation.

Still another object of the invention is to carry out the averagingreaction in the presence of an amount of the lighter hydrocarbonfraction in excess of that entering into the reaction, and in which theexcess of the lighter hydrocarbon fraction may be recycled to theaveraging re-- action in a continuous or semi-continuous process.

A further object of the invention is to carry out the above process,utilizing a pentane frac-.

tion containing normal pentane in excess of that entering into thereaction, fractionating the excess to remove all or a portion ofisobutane or isopentane which is formed during the averaging reaction ifdesired and recycling the balance of the lighter fraction to thereaction zone.

Still a further object of the invention is to carry out the abovereactions in the liquid .phase in the presence of a liquid catalystcomprising primarily hydrogen fluoride and promoted by a minorproportion of boron trifluoride, and if desired, also promoted by thepresence of an unsaturated hydrocarbon.

Another object is the provision of a process in which fluoridescontaining the impurities present in commercial grades may be used.

An additional object of the invention is to carry out the pentaneaveraging process under conditions of temperature and pressure not lowernor higher than can be obtained conveniently in ordinary plantoperations.

The invention has as a further object the provision of a process of thecharacter described in which the activity of the catalyst, in additionto being controlled by variations in temperature, pressure and otherfactors ordinarily employed in catalytic operations, also can becontrolled readily by means of the partial pressure of the borontrifluoride constituent of the catalyst.

Still a further object is the provision of a process of averaging asdescribed in which the catalyst can be readily recovered and reused.

Other objects of the invention will appear from the followingdescription.

In carrying out the process of the invention, a lighter hydrocarbonfraction comprising normal pentane is mixed with the heavier boilingfraction, such as a normally liquid hydrocarbon. These are caused toreact preferably in a liquid state, in the presence of a liquid catalystand under conditions of temperature and pressure as will be pointed outmore particularly hereinafter, to produce products heavier than thelight hydrocarbon and lighter than the heavier hydrocarbon startingmaterials. At the conclusion of the treatment the hydrocarbons areseparated as one phase and may be fractionated, and the catalyst isseparated as another phase. The catalyst phase may be reused as such ormay be regenerated and reused.

The light hydrocarbon may be normal pentane or a mixture of normal andisopentane. It may also be a mixture of normal (or normal and iso-)pentane with normal butane or a mixture of normal and isobutane. Normalpentane is readily reacted in accordance with the invention and since itis not of great value in itself as a motor fuel, the invention assumesparticular importance with reference to its use as the lighter reactingcomponent.

The lighter hydrocarbon fraction may be obtained from any refineryoperation; it is immaterial if it contains small amountsof otherconstituents, and for this reason it need not be highly purified. It isalso immaterial, and in fact it is an advantage as pointed out later, ifit contains a small amount of unsaturated hydrocarbons. For this reasonit is not necessary to fractionate the unsaturated hydrocarbons andother ingredients from the lighter fraction. Generally the normalpentane is found mixed with some isopentane and no harm is done if thelatter is present. Under some conditions the reaction may be facilitatedby the presence of isopentane. However, since isopentane is more usefulin itself as a motor fuel, the ability to use normal pentane as arawmaterial in the averaging process is of great importance. If thelighter fraction contains butanes, as it may especially in a continuousprocess, the presence of the latter does not interfere with the netconsumption of the normal pentane.

In a continuous operation in which an excess of the lighter fraction isused, a part of the normal pentane may be isomerized to isopentane and apart converted to isobutane. When the excess of the lighter fraction isrecycled the amounts of the isopentane and/orisobutane in the recycledfraction may be varied and this becomes a controllable variable.

The heavier fraction, in general, should be a heptane or heavierhydrocarbon. While the heavier fraction may be a pure hydrocarbon,generally it will be a mixture, such as naphthas (250-400" F), kerosenes(350-550 F), light gas oils MOO-625 F), heavy gas oils (SOD-710 F),mixtures of light and heavy gas oils lOO-l'lO F), deasphaltized anddearomatized residues (above 700 F), the portion of crude boiling to 550F., the portion of crude boiling to 700 F., the portion of crude oilboiling between 250-710 F., mixtures of naphthas with kerosenes, and

fractions boiling higher than 825 F. In these stocks the presence ofhydrocarbons lower than heptanes is no disadvantage. Other stocks thatmay be used are Fischer-Tropsch (Hz-l-COY tain normal hydrocarbons,isomers, napthanes or small amounts of hydrocarbons other than normal orunsaturated hydrocarbons. The latter may be beneficial as mentionedheretofore.

In some instances both the light and the heavier fractions to be reactedin the process may be in the form of a single fraction. For example, astock boiling from 70 to above 400 F., or crude oil or reduced crude assuch, may be used in the averaging reaction.

The presence of aromatics in the feed stocks, particularly in theheavier fraction where they are more apt to be present, is undesirablebecause these aromatics tend to form a complex with the catalyst anddecrease its activity. For this reason it is desirable that the feedstock should contain a minimum of aromatics. While it is not essentialthat the stock be free from aromatics if other conditions are adjustedsuitably, it will be generally preferable at least to reduce thearomatic content of the stock somewhat by a dearomatization process ifthe stock is high in aromatics. This may be done by any meansconventional in the art, such as solvent extraction, or the fluoridesmay be used for dearomatizing in accordance with the process describedin my Patent No. 2,343,744, granted March 7, 1944. p

The ratio of the light to the heavier fraction may vary over arelatively wide range. Generally it is preferred to have at least i molof the lighter fraction per mol of the heavier fraction. Two to 6 molsof the light fraction per mol of the heavier fraction is the preferredrange. There is no object in having present more of the lighter fractionthan will reflect an improvement, since there is no point in recycling alarger excess of this fraction than can accomplish a correspondingimprovement in the reaction.

The catalyst used in the process comprises hydrogen fluoride promotedwith a minor proportion of boron trifluoride therein, and in someinstances with an olefin. It is used preferably in the liquid phase.

Hydrogen fluoride boils at about 67 F. and is therefore a liquid attemperatures just under room temperature and may be kept liquid athigher temperatures by moderate pressures. The temperatures andpressures used in the process of the invention are conveniently thosethat maintain the hydrogen fluoride liquid. Boron trifluoride boils at-l50 F. and is a gas at the temperatures and pressures convenientlyemployed in hydrocarbon treating processes. However, boron trifluoridedissolves in liquid hydrogen fluoride to agiven extent and the amountwhich dissolves at any given temperature depends on the partial pressureof boron trifluoride. At higher partial pressures, a larger amount ofboron trifluoride is dissolved.

The boron trifluoride in the hydrogen fluoride in the liquid phasepossibly may react at least to some extent, but an understanding of thechemistry involved is not necessary to practice my invention, and I donot intend to be bound by any theory. At any event the amount of theboron trifluoride in the hydrogen fluoride, which controls the activityof the catalyst, is a function of the partial pressure of the borontrifluoride.

The amount of boron trifluoride dissolved in the hydrogen fluoride, atany given temperature, may be expressed conveniently in terms of thepartial pressure of boron trifluoride. This may vary, in accordance withthe invention, from 5 to 1000 Pounds per square inch; generally about 50to 300 pounds .per square inch will be used. However, the partialpressure should under no circumstances be such that the amount of borontrifiuoride exceeds 50 mol per cent of the'fluorides' With the partialpressures usually used the amount does not exceed mol per cent. Thewords dissolved and solution are used as generic to both a physicaladmixture and a reaction product.

One of the advantages of the process of the invention is the ability tocontrol the reaction by adjusting the activity of the catalyst throughcontrol of its composition. This may be accomplished by varying thepartial pressure of the boron trifluoride, because a change in thispartial pressure results in a change in the amount of boron trifiuoridedissolved. If the partial pressure of the boron trifluoride isincreased, by admitting boron trifluoricle to the reaction zone from ahigh pressure source of supply, the activity of the catalyst is greaterunder conditions otherwise the same. If this partial pressure isdecreased, by bleeding boron trifluoride, the ac tivity of the catalystis reduced.

If an olefin is added, or is present in the reaction zone in an amountless than that which acts as a poison, the olefin appears to act as apromoter. The available evidence indicates that the olefin acts as ;ahydrogen acceptor and that the hydrogen fluoride-boron trifluoridesolution or the reaction product may form a new compound or chemicalcomplex with the olefin. Since olefins may be formed in the process,especially when heavier stocks are used, the addition of an olefin as aseparate addcd'ingredient to the stocks may not reflect a separateimprovement.

The catalyst to be used in practicing the invention, therefore, may beviewed as hydrogen fluoride promoted by a minor proportion of borontrifluoride; or it may be viewed as hydrogen fluoride promoted by bothboron trifiuoride and an olefin; or a combination of both fluoridespromoted by the olefin. The presence of an olefin generally givessomewhat better results.

The hydrogen fluoride and boron trifluoride may be the availablecommercial grades. It is not necessary to have chemically :purefluorides. The impurities in the commercial grades, including water,which are generally present in an amount of about A; to 5 per cent, donot interfere materially with the operation of the catalyst. In view ofthe economic advantage of using the commercial grade, .it is preferred,and was used in the following examples. Reference to the fluorideshereinafter is intended to include such commercial grades and theirnormal impurities or their equivalent in composition.

The conditions under which the process is carried out are selectedwithin convenient ranges so as to produce maximum yields. In general thetemperature may vary from to 400 F., preferably from about 20 to 212 F.Averaging with kerosene as the heavier stock shows that the process canbe carried out conveniently at a temperature within a range of about 32to 150 F. It is an advantage of the process that extreme temperatures ineither direction are not necessary. A single temperature may be usedthroughout the reaction, or it may be varied during the reaction. If thecatalyst is reused a somewhat higher temperature may be desirable thanis the case when the catalyst is fresher. It may be desirable, for thisreason, to operate with ascending temperatures in the direction of flow.

duce a given amount of product.

This may enable a reduction in the amount of catalyst per unit of theproduct formed, and may also have a beneficial effectin causing some ofthe hydrocarbons to shift from the catalyst phase of the reaction to thehydrocarbon phase. The amount of the catalyst employed must beconsidered with reference to both of the fluoride ingredients comprising:it. The amount of the hydrogen fluoride may be 5 to 1300 volume percent based on the hydrocarbons to be treated when in liquid form,preferably-the amount should be about 15 to 1.00 volume per cent.Amounts as low as 1 volume per cent may be used in a multistagetreatment in which the total would be at least 5%. The use ,of largeramounts increases the rate of conversion and the yield ina given timeunder conditions otherwise the same. The amount used may depend. to alarge extent upon the economics involved and the maximum conversiondesired per pass .of the material. The total amount necessary may alsobe less if it is supplied in increments'during the reaction. If desiredthe used catalyst may be removed before the next increment is supplied.-No more-is used than is necessary to efiect the desired reaction in thedesired time since to use more would only add to the amount to berecovered or regenerated. I

The amount of the boron fluoride used, as expressed in termso-f partialpressure, has been indicated heretofore in describing the composition ofthe catalyst.

When an olefin is added separately as an ingredient it may vary fromextremely small amounts to or more mol per cent based on the amount ofthe boron trifluoride dissolved in the hydrogen fluoride. Expressed inpractical terms, the amount of the olefin may be to based on thehydrocarbons being treated.

The total pressure .should be .sufficient to keep the hydrogen fluoridein the liquid phase, and preferably also to keep all the hydrocarbons inthe liquid phase. It must, of course, exceed the partial pressure of theboron trifluoride. The total pressure may vary up to 1000 pounds persquare inch, such as might be obtained by the presence of an inert gas,but generally no advantage is gained (un'less hydrogen is used as .de-

scribed later) by -having a total pressure greater than the sum .of thepartial pressure of the boron trifluoride and the partial pressures ofthe hydrogen fluoride and the hydrocarbons at the temperature utilized.

The time of contact between the pentane and other hydrocarbons and thecatalyst may vary with the temperature, thoroughness of contact ormixing between the hydrocarbon and the catalyst, and other factors.Depending upon such other factors, the time should be selected to giveoptimum yields. This may be from 5 minutes to 3 hours, although in thehigher temperature ranges and with very thorough mixing, as

might be accomplished with the best commercial mixing apparatusavailable, the time might be reduced to the order of a minute. In acommercial operation, it is desirable, of course, to keep the reactiontime as short as possible since this decreases the size of the reactornecessary to pro- Observations indicate .that the reaction proceedsquite quickly, and readily reaches :a condition where more time does notmaterially alter the distribution of the products to such an extent thatit .is of economic advantage to continue the reaction longer.

The .agitation may be accomplished with any an orifice under highpressure.

The temperature, composition of the catalyst,

time of contact, and other factors mentioned heretofore are more or lessinterdependent. The

ranges described heretofore are not intended to mean that anytemperature may be used with any length of time or any composition ofcatalyst to obtain the identical result. For example, if a lowertemperature is used, a somewhat larger amount of catalyst may be presentor a somewhat higher partial pressure of boron trifluoride may be used,or the treating time may be longer, or mixing better, or any or all ofthem, to obtain about the same result that would be obtained with ahigher temperature and with a lesser amount of catalyst, or a lowerpartial pressure of boron trifluoride, or with a, shorter treating time.Thus, for example, any temperature within the range may be employed andthe other variables may be adjusted within their ranges so as to obtainaveragingiwith pentane.

It is a particularly important part of the process that in addition tovarying the time of contact, the amount of catalyst, and thetemperature, which are the variables with which the prior art has had towork, it is possible, in accordance with the process to vary thecomposition of the catalyst by varying the partial pressure of the boronfluoride. Thus, for any given temperature, time of contact, etc., atwhich it is desirable to operate because of plant equipment or economicreasons, the activity of the catalyst and the rate of the pentaneaveraging reaction can be varied into the reaction in an amount toprovide a partial pressure of hydrogen of 100 to 1000 pounds per squareinch. This tends to minimize the amount of hydrocarbons entering thelower layer.

The process is adapted either for batch operation or for continuousoperation. In either type of operation the feed stocks may be dried, ifdesired, by suitable driers. In a batch operation the pentane-containingfraction and the higher hydrocarbons are brought together with thefluorides in the desired amounts in a closed container or autoclavewhere they are preferably subjected to agitation and maintained underthe desired temperature and pressure for the required length of time. Ina continuous process the fluorides and the hydrocarbons to be treatedare fed into a continuous type mixer, for example, a three-stage mixer,and maintained at the desired temperature and under the appropriatepressure. The flow through the mixer may be intermittent or continuousand may be adjusted so that the hydrocarbons are in contact with thecatalyst for the desired length of time.

In either the batch of continuous operation, if an olefin is to be addedas a promoter, this may be contained in either of the pentane or other'raw materials or may be introduced separately or absorbed in thefluorides. If hydrogen is to be used, thismay' be introduced from aseparate high pressure source of the supply.

The order of mixing the components is not critical. Thepentane-containing fraction and heavier hydrocarbons may be fedseparately or .mixed and introduced into the fluorides or vice versa.Alternatively the pentane-containing component may be mixed with thefluorides and this mixture fed gradually to the heavier hydrocarbons orvice versa in one or more stages. In

I either a batch or continuous process, the fluorides may be introducedin increments at different intervals during the total reaction period.When using a continuous mixer having a plurality of stages, thefluorides may be introduced at each stage. The operation may becountercurrent or concurrent.

In a multiple treatment process the first treatment with the catalystmay be largely or in part one of dearomatizing, and subsequenttreatments may be responsible for the major portion of the pentaneaveraging reaction. Although the catalyst may be reduced in activityduring the averaging reaction so as to render it ineffective for furtherreacting pentane, it may still be used to dearomatize and the.dearomatization of the heavier fraction feed stock with the usedcatalyst from the pentane averaging reaction is an important aspect ofthe invention. This could be accomplished, for example, in a two-stagecountercurrent treatment. The catalyst containing the aromatics may thenbe subjected to a regenerating action in accordance with any of theprocesses indicated heretofore, and the fluorides returned to theaveraging zone.

The following examples are given merely as illustrative of the resultsthat may be accomplished when the invention is practiced on a laboratoryscale. This may be transferred to a commercial basis with the incidentimprovements as described heretofore.

Example 1 An Illinois kerosene, containing 16% aromatics was used as theheavier stock for averaging with a pentane fraction. Five per cent ofthe kerosene boiled below 360 F. and 50% below 425 F.; the end point was551 F. The process was carried out in a two stage treatment. In thefirst stage the kerosene was treated with 15 volume per cent of liquidhydrogen fluoride (based on the volume of the kerosene) in which borontrifluoride was dissolved in an amount to provide a partial pressure of150 pounds per square inch. The reaction was continued for 15 minutes atF. by agitating the kerosene and the catalyst. After the kerosene andthe catalyst have been mixed under the above conditions for the statedtime, the agitation was discontinued and the catalyst phase and thehydrocarbon phase, being mutually insoluble in each other, was separatedby gravity. If desired, forces greater than gravity, such ascentrifuging, could be used in effecting the separation. The lighter orupper layer contains the hydrocarbons and the lower layer comprises thecatalyst phase. This separating operation was carried out under thepressure used in effecting the reaction.

7 The upper layer and 400 volume per cent of a pentane fraction wasplaced in the second stage reaction vessel in the presence of volume percent of liquid hydrogen fluoride (based on the volume of the kerosene)in which boron trifluoride was dissolved in an amount to provide apartial pressure of 150 pounds per square inch under the reactionconditions. The mixture .is agitated at a temperature of 90 F. for a pe-Hydrocarbons produced (weight per cent of the total hydrocarbonscharged) Hydrocarbons charged (weight per cent) Hydrocarbon Propane andlighter Hydrocarbons in catalyst phase -I:

From the above reaction it will be seen that there is a net productionof 14.3% boiling within the range of hexane to 300 F. There is a sinificant consumption of kerosene and a large consumption of the pentanefraction, particularly anet consumption of the normal pentane to resultin these valuable intermediate boiling hydrocarbons.

The fraction boiling above 300 F. comprising 21.8% can be recycled tothe reaction zone as well as the pentanes and butanes, if desired. Sincethis stock is substantially aromatic free there would be less lowerlayer hydrocarbon in such a continuous process.

If desired, the fraction boiling from isopentane to 300 F. may beseparated. This amounts to 39% of the hydrocarbons charged and is a goodgrade of gasoline in View of the small amount of normal pentane. Thebutane fraction may be used in alkylating or may be recycled to thereaction zone and mixedwith the fresh charge of pentanes.

The consumption of kerosene is not as large as in thefollowing examples,but the process is a desirable one in making a hexane to 300 F. gasolinefrom pentanes. The incidental isobutane formation is desirable since itis a valuable intermediate product.

Example 2 If the entire butane-pentanes fraction from Example 1 is to berecycled or if the butanes are to be recycled with the addition of afresh charge of pentane, the results that may be obtained are indicatedin this example, in which a mixture of butanes and pentanes(approximating the butanes-pentanes fraction from Example 1) is used asthe light stock. This light fraction, in an amount of 400 volume percent (based on the kerosene) is averaged with a kerosene, with the samecatalyst and in the same amount, and for the same length of time as inExample 1. The kerosene used contains about 6% aromatics, about of thetotal hydrocarbons boiling be- 10 low 300F. and about 31% boiling below400 F. The results are as follows:

Hydrocarbons probHydil locar-d ducgcti in g ons c arge weig 11er- Hydlocmbon (weight percent of the cent) total hydrocarbons charged) Propaneand lighter 0 0. l Isobutane 35. 9 42. 3 Normal butane 4. 9 9. 3Isopentane 25. 6 l5. 5 Normal pentane.. 8.0 3. 3 Hexane to 300 F l. 215.0 300 to 400 F 7.9 2. 4 Above 400 F l6. 5 8. 2 Hydrocarbons incatalyst phase. 3. 9

It will be seen that there is a net production of hydrocarbons boilingin the hexane to 300 F. range and a substantial net consumption of thekerosene and a net consumption of the pentane fraction, particularly ofthe normal pentane. While there is an increase in the amount of butanesfrom 40.8%. to 51.6%, this increase is less than the amount of theheavier fraction and the lighter fraction consumed, indicating the theaccomplishment of averaging.

By extrapolation ofthe data from the above two examples, and by furtherresearch, it has been ascertained thatupon recycling the entire lighterfraction the amount of butanes may be expected to increase until theyrepresent about 80% of the lighter fraction. At this stage there will bea net consumption of both the butanes and the pentanes in the averaging.

The above examples are given merely as illustrative of the results thatmay be accomplished and not as a limitation upon the scope of theinvention as described heretofore.

In the above examples the upper layer comprising the hydrocarbons may besent to a primary fractionating column and the excess of lighterfraction and any fluorides dissolved in the upper phase may be separatedat the top of the column and recycled to the reaction zone. Since anexcess of the lighter fraction in the reaction zone is preferable, apart of the feed for for the reaction in a continuous process maycomprise the recycled lighter fraction and fresh pentane feed. Theamount of the fresh feed stock need be only equal to that which isconsumed in the averaging reaction and itmay be all normal pentane.

During the averaging process the normal pentane fed into the averagingreaction zone may become at least partially isomerized and alsoconverted to butanes as shown in the examples. The lighter componentsthat are taken from the top of the primary fractionating' column may befurther fractionated in one or more secondary fractionating columns toseparate a portion or all of the isobutane for use in other processes,such as alkylation, and the remainder of the excess of the lighterfraction may be returned to the averaging zonep When the alkylation isto be accomplished" with the same catalyst it isnot necessary toseparate any fluorides that may distill with the isobutane. Similarlyisopentane may be fractionated if it is not to be recycled or taken offin the gasoline fraction. Thus the invention contemplates the abilitynot only toutilize the normal pentane and convert it into a highermolecular weight hydrocarbon, but at the same time to convert normalpentane to 11 isopentane and isobutane, -a portion-of which may bewithdrawn and used in other reactions.

The lighter fraction separated for recycling may be depropanized byfractional distillation, absorption, or any other fractionation orsuitable method before recycling, if the propane builds up to anundesirable level.

The wanted products may be withdrawn fro intermediate plates in theprimary fractionating column.

The heavier unconverted products may be withdrawn from the bottom of thecolumn. These may or may not be recycled to the reaction zone, dependingupon their character, or they may befurther fractionated and a partreturned to the reaction zone.

If desired, a single product, such as isopentane or neo-hexane or amixture boiling from about 75 to 141 F. (since only a small amount ofnormal pentane remains after the reaction process) may be withdrawn fromthe fractionating column and all of the lighter (butanes) and all of theheavier (normal hexane and heavier) materials maybe recycled to theaveraging reaction zone. This will shift the conditions in the averagingreaction so as to form primarily the product being withdrawn. Thepentane averaging process thus may be used essentially for making asingle wanted product with the return of all other products as rawmaterials.

The lower layer or catalyst phase is separated from the hydrocarbons atsuch a temperature and pressure that the catalyst remains as a distinctliquid phase, in accordance with the preferred embodiment, the catalystphase may be recycled and reused for the treatment of a fresh supply ofraw materials or such as in the countercurrent system for dearomatizingmentioned heretofore. The used catalyst phase may also be employed inother averaging operations which require a less active catalyst. Forexample, the catalyst may be used initially on a stock which isdiflicult to react and after separation from said stock, it may bereused with stocks that are.

easier to react. Alternatively the used catalyst phase may be used as analkylation catalyst where a less active catalyst is required.

Certain hydrocarbons, notably unsaturates and aromatics, tend toaccumulate in the catalyst phase in the form of a complex during theaveraging reaction. In the above examples it will be noted that thecatalyst phase contains a slight amount of hydrocarbons. A small amountof a complex with an unsaturate in the catalyst phase is thought to behelpful as a promoter, and for this reason the presence of an olefin hasbeen indicated as desirable. But the accumulation of too muchhydrocarbon in the catalyst phase exerts a poisoning effect. Therefore,if the amount of hydrocarbon in the catalyst phase is keptat the optimumvalue, the reaction will proceed more rapidly and less of the catalystwill be required.

To overcome this poisoning effect, a part or all of the used or reusedcatalyst may be withdrawn and subjected to a relatively hightemperature, for example, 250-600 F. This may be by way of a pot still,or by means of flash distillation. Preferably a two-stage treatment isemployed, the first stage using a flash distillation at a somewhat lowertemperature, preferably at system pressure followed by distillation in astripper at a higher temperature and lower pressure. At this temperaturesubstantially all of the fluorides are liberated as gases These can 12be collected and condensed and/or compressed and returned to the mixingzone or stored or otherwise used.

Alternatively, instead of distilling the fluorides, the lower layer orcatalyst phase may be treated with a material which exerts a solventaction on the fluorides and which is immiscible with the hydrocarbons inthe lower layer, or which forms a chemical compound or complex with thefluorides, and from which the fluorides may be released later, forexample, by heating.

Fluorides can be extracted from the upper or lower layers, for example,with an oxyfluoboric acid, such as H3BF2O2 or H4BF'3O2.

The reference .to a hydrocarbon fraction is intended to refer to a purehydrocarbon as well as a mixture of hydrocarbons.

It will be apparent that the invention is capable of many applicationsand variations and I intend all of them to be included as are within thefollowing claims.

This application is a continuation-in-part of applications Ser. No.422,744, filed December 12, 1941; Ser. No. 451,216, filed July 16, 1942,and Ser. No. 529,681, filed April 5, 1944.

I claim:

1. A process of catalytically averaging hydrocarbons which comprisesreacting a normally liquid hydrocarbon fraction comprising paraflinichydrocarbons having at least seven carbon atoms and a lighterhydrocarbon fraction comprising normal pentane, in the presence of aliquid catalyst the inorganic ingredients of which comprise essentiallyliquid hydrogen fluoride in which is dissolved not over 50 mol per centof boron trifluoride, and continuing the reaction under a pressure tomaintain the hydrogen fluoride liquid and at a temperature and for aperiod of time while regulating the activity of the catalyst byadjusting the partial pressure of the boron trifluoride to result in anet production of hydrocarbons intermediate said liquid hydrocarbonfraction and said normal pentane.

2. A process of catalytically averaging hydrocarbons, which comprisesreacting a normally liquid petroleum fraction boiling higher thangasoline, and a hydrocarbon fraction comprising normal pentane, in thepresence of a liquid catalyst the inorganic ingredients of whichcomprise essentially liquid hydrogen fluoride in which is dissolved notover 50 mol per cent of boron trifluoride, and continuing the reactionunder a pressure to maintain the hydrogen'fluoride liquid and at atemperature and for a period of time while regulating the activity f thecatalyst by adjusting the partial pressure of the boron trifluoride toresult in a net production of hydrocarbons intermediate said liquidpetroleum fraction and said normal pentane.

3. A process of catalytically averaging hydrocarbons, which comprisesreacting kerosene and a hydrocarbon fraction comprising normal pentaneand isopentane, in the presence of a liquid catalyst the inorganicingredients of which comprise essentially liquid hydrogen fluoride inwhich is dissolved not over 50 mol per cent of boron trifluoride, andcontinuing the reaction under a pressure to maintain the hydrogenfluoride liquid and at a temperature and for a period of time whileregulating the activity of the catalyst by adjusting the partialpressure of the boron trifiuoride to result in a net production ofhydrocarbons intermediate said kerosene and said pentanes.

4. A process of catalytically averaging hydrocarbons, which comprisesreacting a normally liquid hydrocarbon fraction comprising paraffinichydrocarbons having at least seven carbon atoms and a butanes-pentaneshydrocarbon fraction comprising normal pentane, in the presence of aliquid catalyst the inorganic ingredients of which comprise essentiallyliquid hydrogen fluoride in which is dissolved not over 50 mol per centof boron trifluoride, and continuing the reaction under a pressure tomaintain the hydrogen fluoride liquid and at a temperature and for aperiod of time while regulating the activity of the catalyst byadjusting the partial pressure of the boron trifluoride to result in anet consumption of said liquid hydrocarbon fraction and said normalpentane, and to produce hydrocarbons intermediate said liquidhydrocarbon fraction and said pentanes.

5. A process of catalytically averaging hydrocarbons, which comprisesreacting a petroleum fraction boiling higher than gasoline and abutanes-pentanes hydrocarbon fraction comprising a normal pentane, inthe presence of a liquid catalyst the inorganic ingredients of whichcomprise essentially liquid hydrogen fluoride in which is dissolved notover 50 mol per cent of boron trifluoride, and continuing the reactionunder a pressure to maintain the hydrogen fluoride liquid and at atemperature and for a period of time while regulating the activity ofthe catalyst by adjusting the partial pressure of the boron trifluorideto result in a net consumption of said petroleum fraction and saidnormal pentane, and to produce hydrocarbons intermediate said petroleumfraction and said pentane.

6. A process of catalytically averaging hydrocarbons, which comprisesreacting a lighter hydrocarbon fraction comprising normal pentane and aheavier hydrocarbon fraction comprising primarily hydrocarbons having atleast seven carbon atoms in a reaction zone in the presence of a liquidcatalyst, said catalyst comprising essentially liquid hydrogen fluoridein which is dissolved less than 50 mol per cent of boron trifluoride asthe primary inorganic catalytic ingredients, and continuing the reactionunder a pressure to maintain the hydrogen fluoride and the hydrocarbonsliquid and at a temperature and for a period time while regulating theactivity of the catalyst by adjusting the partial pressure of the borontrifluoride to result in a net production of hydrocarbons intermediatesaid normal pentane and said heavier fraction, separating the catalystphase from the hydrocarbons, separating the fluorides from the catalystphase, and recycling the separated fluorides to the,

reaction zone.

7. A process of catalytically averaging hydrocarbons, which comprisesreacting a lighter hydrocarbon fraction comprising normal pentane and aheavier hydrocarbon fraction comprising primarily hydrocarbons having atleast seven carbon atoms in a reaction zone in the presence of a liquidcatalyst, said catalyst comprising essentially liquid hydrogen fluoridein which is dissolved less than 50 mol percent of boron trifluoride asthe primary inorganic catalytic ingredients, and continuing the reactionunder a pressure to maintain the hydrogen fluoride and the hydrocarbonsliquid and at a temperature and for a period of time while regulatingthe activity of the catalyst by adjusting the partial pressure of theboron trifluoride to result in a net production of hydrocarbonsintermediate said normal pentane and said heavier fraction, separatingthe catalyst phase from the hydrocarbon phase, fractionating thehydrocarbon phase and recycling at least part of the unreacted lighterhydrocarbon fraction to the reaction zone.

8. A process of catalytically averaging hydrocarbons, which comprisesreacting a lighter hydrocarbon fraction comprising normal pentane and aheavier hydrocarbon fraction comprising primarily hydrocarbons having atleast seven carbon atoms in a reaction zone in the presence of a liquidcatalyst, said catalyst comprising essentially liquid hydrogen fluoridein which is dissolved less than 50 mol per cent of boron trifluoride asthe primary inorganic catalytic ingredients, and continuing the reactionunder a pressure to maintain the hydrogen fluoride and the hydrocarbonsliquid and at a temperature and for a period of time while regulatingthe activity of the catalyst by adjusting the partial pressure of theboron trifluoride to result in a net production of isopentane andhexanes, separating the catalyst phase and the hydrocarbon phase,iractionating the hydrocarbon phase to separate a single wanted fractionboiling between isopentane and hexane isomers, and recycling at leastpart of the remaining heavier hydrocarbons to the reaction zone.

9. A process of catalytically averaging hydrocarbons, which comprisesreacting a lighter hydrocarbon fraction comprising normal pentane and aheavier hydrocarbon fraction comprising primarily hydrocarbons having atleast seven carbon atoms in the presence of a liquid catalyst, saidcatalyst comprising essentially liquid hydrogen fluoride in which isdissolved less than 50 mol per cent of boron trifluoride as the primaryinorganic catalytic ingredients, and continuing the reaction under apressure to maintain the hydrogen fluoride and the hydrocarbons liquidand at a temperature and for a period of time while regulating theactivity of the catalyst by adjusting the partial pressure of the borontrifluoride to result in a net production of isobutane and hydrocarbonsintermediate the pentane and said heavier fraction, separating thecatalyst phase and the hydrocarbon phase, fractionating the hydrocarbonphase to separate isobutane as one fraction and said intermediatehydrocarbons as another fraction.

10. A process of catalytically averaging hydrocarbons which comprisesreacting a butanespentanes hydrocarbon fraction comprising normalpentane and a petroleum fraction boiling above gasoline in a reactionzone in the presence of a liquid catalyst, said catalyst comprisingessentially liquid hydrogen fluoride in which is dissolved less than 50mol per cent of boron trifluoride as the primary inorganic catalyticingredients, and continuing the reaction under a pressure to maintainthe hydrogen fluoride and the hydrocarbons liquid and at a temperatureand for a period of time while regulating the activity of the catalystby adjusting the partial pressure of the boron trifluoride to result ina net consumption of said normal pentane and said petroleum fraction,and to produce hydrocarbons intermediate said normal pentane and saidpetroleum fraction, separating the catalyst phase from the hydrocarbonphase, separating fluorides from the catalyst phase and recycling theseparated fluorides to the reaction zone, fractionating the hydrocarbonphase and recycling to the reaction zone at least part of thehydrocarbons lighter than said intermediate hydrocarbons.

ROBERT E. BURK.

